Catheters have been used for many years to deliver therapeutic agents to patients. In many instances, catheters are implanted in patients that have been diagnosed with diseases that require long-term therapeutic treatment. Diseases that may require catheter implantation include Alzheimer's, Huntington's, epilepsy, neuro-degenerative disorders, and brain tumors. When treating these types of diseases a need arises to deliver therapeutic drugs to multiple locations simultaneously. For example, the difficulty with treating brain tumors is effectively delivering the therapeutic agent to the tumor and the surrounding tissue that is not located near or in the tumor bed. In the case of a patient with a primary brain tumor such as glioblastoma, the tumor and surrounding tissue that may have been infiltrated by cancer cells should be treated. If these outlying tissues are not treated, the tumor may return. Current technology would require the use of multiple separate catheters and pumps to ensure the equal delivery of therapeutics to the tumor and the outlying tissues. The reduction in the number of catheters and the use of a single pump would make a significant improvement over the current treatment practice.
Additionally, in some cases it is optimal to deliver a therapeutic agent through multiple holes rather than through a single hole. Delivery in this manner would promote diffusion of a therapeutic. U.S. Pat. No. 5,720,720 describes convention-enhanced delivery into a brain and other tissue structures using a catheter with a plurality of slit opening symmetrically spaced around the circumference of the catheter. These slit opening function as valves because the slits remain closed until fluid pressure within the catheter forces the slit valves open.
Catheters for simultaneously providing therapeutics to different locations utilizing a single pump have not been available because of the problem of ensuring equal drug diffusion. Presently, multiple hole single catheters are limited to openings that are circumferentially placed along the catheter usually spaced equidistantly apart. Therefore, the only way to achieve fluid distribution at different locations along a longitudinal path is to use multiple pumps and catheters or to use multiple pumps attached to an Image Guided Neurologics Array delivery catheter. The Image Guided Neurologics Array delivery catheter contains multiple catheters each requiring a separate pumping source. Utilizing multiple catheters or pumps increases the risks of surgical complications and adds complexity to the procedure. In addition, it increases cost and patient discomfort.
There exists, therefore, a significant need for a catheter that can distribute therapeutic agents to multiple locations utilizing a single catheter or a single pump. The present invention addresses this need and relates to an improvement in catheters used to administer therapeutic agents to patients.